airflow-dags/reference/providers/amazon/aws/hooks/glue_catalog.py

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"""This module contains AWS Glue Catalog Hook"""
from typing import Optional, Set

from airflow.providers.amazon.aws.hooks.base_aws import AwsBaseHook


class AwsGlueCatalogHook(AwsBaseHook):
    """
    Interact with AWS Glue Catalog

    Additional arguments (such as ``aws_conn_id``) may be specified and
    are passed down to the underlying AwsBaseHook.

    .. seealso::
        :class:`~airflow.providers.amazon.aws.hooks.base_aws.AwsBaseHook`
    """

    def __init__(self, *args, **kwargs):
        super().__init__(client_type="glue", *args, **kwargs)

    def get_partitions(
        self,
        database_name: str,
        table_name: str,
        expression: str = "",
        page_size: Optional[int] = None,
        max_items: Optional[int] = None,
    ) -> Set[tuple]:
        """
        Retrieves the partition values for a table.

        :param database_name: The name of the catalog database where the partitions reside.
        :type database_name: str
        :param table_name: The name of the partitions' table.
        :type table_name: str
        :param expression: An expression filtering the partitions to be returned.
            Please see official AWS documentation for further information.
            https://docs.aws.amazon.com/glue/latest/dg/aws-glue-api-catalog-partitions.html#aws-glue-api-catalog-partitions-GetPartitions
        :type expression: str
        :param page_size: pagination size
        :type page_size: int
        :param max_items: maximum items to return
        :type max_items: int
        :return: set of partition values where each value is a tuple since
            a partition may be composed of multiple columns. For example:
            ``{('2018-01-01','1'), ('2018-01-01','2')}``
        """
        config = {
            "PageSize": page_size,
            "MaxItems": max_items,
        }

        paginator = self.get_conn().get_paginator("get_partitions")
        response = paginator.paginate(
            DatabaseName=database_name,
            TableName=table_name,
            Expression=expression,
            PaginationConfig=config,
        )

        partitions = set()
        for page in response:
            for partition in page["Partitions"]:
                partitions.add(tuple(partition["Values"]))

        return partitions

    def check_for_partition(
        self, database_name: str, table_name: str, expression: str
    ) -> bool:
        """
        Checks whether a partition exists

        :param database_name: Name of hive database (schema) @table belongs to
        :type database_name: str
        :param table_name: Name of hive table @partition belongs to
        :type table_name: str
        :expression: Expression that matches the partitions to check for
            (eg `a = 'b' AND c = 'd'`)
        :type expression: str
        :rtype: bool

        >>> hook = AwsGlueCatalogHook()
        >>> t = 'static_babynames_partitioned'
        >>> hook.check_for_partition('airflow', t, "ds='2015-01-01'")
        True
        """
        partitions = self.get_partitions(
            database_name, table_name, expression, max_items=1
        )

        return bool(partitions)

    def get_table(self, database_name: str, table_name: str) -> dict:
        """
        Get the information of the table

        :param database_name: Name of hive database (schema) @table belongs to
        :type database_name: str
        :param table_name: Name of hive table
        :type table_name: str
        :rtype: dict

        >>> hook = AwsGlueCatalogHook()
        >>> r = hook.get_table('db', 'table_foo')
        >>> r['Name'] = 'table_foo'
        """
        result = self.get_conn().get_table(DatabaseName=database_name, Name=table_name)

        return result["Table"]

    def get_table_location(self, database_name: str, table_name: str) -> str:
        """
        Get the physical location of the table

        :param database_name: Name of hive database (schema) @table belongs to
        :type database_name: str
        :param table_name: Name of hive table
        :type table_name: str
        :return: str
        """
        table = self.get_table(database_name, table_name)

        return table["StorageDescriptor"]["Location"]